Improvement in guard attachment for locks



UNITED STATES PATENT OFFICE.

PHILO S. FELTER, OF OINCINNATUS, NEW YORK.

IMPROVEMENT IN GUARD ATTACHMENT FOR LOCKS.

Specification forming part of Letters Patent No. 33,933, dated December 17, 1861.

To all whom, it may concern:

Be it known that I, PHILO S. FELTER, of Oincinnatus, in the county of Cortland and State of New York, have invented a new and Improved Guard Attachment for Locks; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure lis an external front view of a lock with my invention applied to it; Fig. 2,asec tion of saine, taken in the line Fig. 3; Fig. 3, a section of same, taken in the line fr', Fig. 2.

Similar letters of reference indicate correspending` parts in the several figures.

The object of this invention is to obtain a simple and eflicient mechanism by which the key-hole of a lock may be guarded, so as to prevent the admission of a key when the lock is in a locked state, land thereby preclude the possibility of the lock being accessible, so as to render picking or the obtaining of impressions to make a key being used as a means to unlock the lock.

The invention consists in the employment or use of a spring in connection -with movable circular slotted disks and movable dials, a key, and guard, all arranged substantially as hereinafter described, whereby the desired end is attained.

To enable those skilled in the art to fully understand and construct my inventionfl will proceed to describe it.

A represents the case 'of a lock.

B is the bolt, which may be operated by a key in the ordinary or in any proper way.

O O are the key-holes of the lock.

D represents what I term a guard, which is formed of a metal bar suspended on a rod or arbor E, which passes through it near its upper end. The bar or guard D is allowed to swing freely on the rod or arbor E, and the lower end of the guard D, when the latter is in use, passes in line with the key-holes C O', so as to effectually prevent the insertion of the key through the front key-hole O. (See Fig. 3.)

The bar or guard D has a dovetail recess a made in it, and in this recess an inverselycorresponding projection b on aspringF fits. This spring F is formed of a flat strip of steel secured within the lower part of the case A, as shown at c. This spring F, by means of its projection b, fitting in the recess a of the bar or guard D, holds the latter in line with the key-hole. C', as will be fully understood by referring to Fig. 2. The upper end of the spring F is provided with four projections dtwo at each side-as shown in Fig. 2, and these projections when the bar or guard D covers the key-hole are in front of circular disks G, which are each provided with a notch c. The disks G are placed loosely on rods or arbors E E F. the arbor E being the one on which the bar or guard D is suspended.

The disks G are connected to the arbors E E E E" by means of pins ex, which are at the ends of arms f on the arbors. of the arbors have screw-threads out on them, and nuts g are placed thereon, said nuts being at the back side of a central plate h in the lock, through which the arbors pass. The outer ends of the arbors project through the front plate of the lock andhave circular disks or dial-plates t' placed loosely on them, said dials being on the outer front side of the case A, and being secured to the arbors by means of pins j, which are at the inner ends of knobs k, said knobs being fastened on the arbors by means of screws Z and the pinsj, fitting in notchesmin the dials 1l. (See Fig. 3.) The dials t' are lettered all around near their edges, and the outer plate of the lock-case is numbered, the numbers extending about half way around thedials fi, as shown clearly in Fig. l.

H is a key, which passes into the baekcase A at such a point as to bear against the spring F. This key is allowed to slide longitudinally in the lock-ease, and itis provided with a bit n, as shown in Fig. 3. The upper end of the bar or guard D is notched, as shown at o, and is curved toward the key H. (See Fig. 2.)

The operation is as follows: Vhen the lock is in a locked state, the bar or guard D is over the key-hole O, and is retained in that position by the spring F, as previously referred to. In order, therefore, to release the bar or guard D, it is necessary to force back the spring F until its projection b is out from the recess a in the bar or guard D, and to effect this the disks G must be so turned that their notches Theinner ends g e will be in line with the projections d ofthe spring F, in order that the projections cl may pass through the notches e, and thus admit of the spring F being forced back. The spring is forced back under the action of the key H, and when forced back the key is turned and its bit n catches into the notch o at the upper end of the bar or guard D, and the lower end of the latter is moved out of line with the key-hole C', so that the key maybe inserted to act upon the bolt B, The disks G are turned in proper position to bring their notches e in a proper relative position with the projections d on the spring F by the aid of the letters on the dialsz' and the numbers on the lock-plate, and changes may be made from time to time by simply shifting the pins e of the armsf in different holes GLX in the disks, the nuts g being unscrewed to admit of the drawing out of the arbors. (See Fig. 3.) The dials may also be shifted for the same purpose by drawing out the pins j from the notches m in the dials i, as shown in Fig. 3.

I am aware that slides have been arranged within locks to pass over the key-holes of the same, in order to prevent the lock being picked or illegitimately opened, and I therefore do not claim,broadly, such device. I am also aware that lettered or numbered dials have been used in connection with numbers on the outer plate of the lock-case to enable circular tumblers to be moved in proper relative position with a bolt, slide, or other dcvioe to guard the key-hole or bolt of the lock. I therefore do not claim, broadly, such parts but I do claim as new and desire to secure by Letters Patent- The bar or guard D, provided with the recess a, in connection with the notched disks G, spring F, provided with the projections b d d, and the key H, arranged substantially as and for the purpose herein set forth.

PHILO S. FELTER. Witnesses:

ABEL N. BARLow, A. J. SMITH. 

